Japanese Patent Application Laid-Open Publication No. 6-202529A has proposed an image forming apparatus which is configured that waste such as residual toner and paper dust is generated as a result of a toner image forming operation and is recovered into a container. To recover waste into the container, a cleaning device is used in the image forming apparatus. The image forming apparatus employs two detecting members (a first detecting member and a second detecting member), each for detecting whether the amount of waste accumulated in the container has reached a corresponding amount.
According to this proposal, before the container is filled up with waste, the first detecting member detects waste, and the image forming apparatus informs a user that the container should soon be replaced by an empty one.
When the container is filled up with waste, the second detecting member detects waste in the container. At this time, the image forming apparatus informs the user that the container has to be replaced with an empty one immediately, and stops operating. This prevents waste from overflowing the container.